peanutsA newly developed skin patch packed with tiny traces of peanut protein could help thousands children who suffer anaphylaxis when they come into contact with the nut.

New figures from Necker Hospital in Paris show youngsters who once faced the threat of a fatal reaction from the tiniest amounts of peanut protein can snack on the nuts after wearing the patch for a year.

The breakthrough patch, called Viaskin Peanut, does not cause anaphylactic shock because the proteins stay in the skin and do not penetrate as far as the bloodstream.

Immune cells recognise peanuts
Worn on the arm or back, it allows minute amounts of the protein to gradually seep through the top layers of the skin.

It then comes into contact with immune system cells which would normally trigger a life-threatening overreaction. But the proteins are in such tiny quantities that the immune cells slowly get used to their presence, learning to recognise peanuts so that they are no longer a threat.

As a result, the body’s defences stop overreacting when they come into contact with peanuts.

Researcher Professor Christophe Dupont said: "The change in peanut consumption represents an important improvement in the quality of life of these patients."

The patch, about the size of ten pence piece, is undergoing trials involving more than 200 patients with severe peanut allergies.

Build up peanut tolerance
The first results from one of the trials, involving children aged five to 17, show that many are able to build up tolerance to peanuts after wearing one for 12 to 18 months.

The volunteers wear a peanut patch or an identical dummy one, changing it for a new one every day.

After 12 months, at least 20 per cent of the children were consuming more than ten times the amount of peanut protein they were able to tolerate at the start of the study.

This equated to about 1.5 peanuts in children who, before the treatment, were at risk of life-threatening anaphylactic shock from the smallest amount of peanut dust – prior to the study some were at risk of death if they were in the same room as someone who was eating peanuts.

Around one in 50 children in the UK has an allergy to peanuts.